The ctrate parameter affects the overall sample rate. The code comment is incorrect, the max sample rate is 256 Hz for the interrupt counter, so a ctrate=2 would give a 128 Hz sample rate. There is a simple lowpass filter in the code (an exponentially weighted moving average) that has a filter param widthfilterparam = 5. That is 5/256=.01953. See http://gregstanleyandassociates.com/whitepapers/FaultDiagnosis/Filtering/Exponential-Filter/exponential-filter.htm On this site a param a is used where a=1-.01953 to relate back to the filter in the code. This results in a time constant of roughly .4 sec. You could change the widthfilterparam to a larger number to reduce the time constant. This will result in a faster sensor output.